The GHK Cu pen works. But needles at home were never the answer. We took the same clinically backed copper peptide complex and put it into a serum you can use in 30 seconds, Have you heard of the peptide GHK Cu?, GHK Cu is one of the most promising peptides for improving skin health. It can promote collagen production, which is essential for skin elasticity and firmness. Neurogan Health, GHK Cu Copper Peptide, Hair & Scalp Serum Neurogan Copper Peptide Hair Scalp Serum for Fuller Softer Shinier Hair Walmart.com